Nobody enjoys their daily commute to and from work. For most, it involves way too many traffic jams and insanely long red lights. But there is another reason to dislike your drive to work that you might not know about. It is during this time that you experience most of your daily exposure to harmful pollutants that can contribute to heart disease and respiratory problems.
Despite the high concentrations of pollutants found on the road, there is something scientists have recently discovered that can help reduce your exposure. It turns out all you need to do is turn on your car’s air conditioner.
To reach this conclusion, scientists tested all the different combinations of air conditioner and fan settings inside vehicles while monitoring pollutants both inside and outside each car. They also tested levels in the car with the windows up and then down. In addition, they tested the pollution levels in various traffic conditions that are common for commuters, including being stuck behind a large diesel-powered vehicle, driving past construction work, stuck in highway traffic, and being stopped at a red light.
What the researchers found is that simply turning on the car’s air conditioner reduced pollutant levels inside the vehicle by up to 34%. This happens even though the air conditioner is pulling air from outside (where the pollutants come from). When the dirty air passes across the cold evaporator of the AC, the cold surface attracted the dirty particles in the air. Thus, they stuck to the evaporator surface instead of being pulled into the car, where a person could breathe them. This is why turning on the air conditioner is more effective at reducing in-car pollution that turning on the fan by itself, which runs the air through the same filter that the air conditioner uses.
AC systems also seemed to offer the most protection when following high-polluting vehicles like large trucks. When following such vehicles, air pollution outside the tested cars was three times higher than inside the car, as long as the air conditioner was on. The scientists also discovered that drivers could further minimize exposure by rolling down their windows once the truck or bus is no longer around. This allows any lingering buildup of pollutants in the car to dissipate. They also recommend rolling down windows for a period of time after exiting a congested freeway, an area that is another major source of pollutants.
If your car’s AC doesn’t work, though, don’t worry too much. The researchers also found that just keeping your windows closed when in heavy-pollution situations helped reduce in-car air pollution between 8 and 44%. Unfortunately, the scientists who conducted this study did not say what to do during the cold winter months, when running the air conditioner in your car is an impossibility.